High power device

Abstract

A high power device including with a first nitride semiconductor layer, a second nitride semiconductor layer formed on the first nitride semiconductor layer, and a third nitride semiconductor layer containing an Al element formed on the second nitride semiconductor layer. The second nitride semiconductor layer is a multiple quantum well layer in which a nitride semiconductor layer containing an In element and a nitride semiconductor layer not containing an In element are alternately stacked.

What is claimed is: 
     
       1. A high power device comprising:
 a first nitride semiconductor layer; 
 a second nitride semiconductor layer formed on the first nitride semiconductor layer, wherein the second nitride semiconductor layer is a multiple quantum well layer in which an InN layer and a GaN layer are alternately stacked; 
 a third nitride semiconductor layer containing an Al element formed on the second nitride semiconductor layer; and 
 a source electrode, a gate electrode and a drain electrode formed on the third nitride semiconductor layer, wherein the source electrode, the gate electrode and the drain electrode are formed separately to each other, and the source electrode and the drain electrode are formed so as to sandwich the gate electrode. 
 
     
     
       2. The high power device according to  claim 1 , wherein:
 a film thickness of the InN layer is not more than 10 nm, and 
 a film thickness of the GaN layer is not more than 20 nm. 
 
     
     
       3. The high power device according to  claim 2 , wherein:
 a number of pairs of the InN layer and the GaN layer in the multiple quantum layer is not more than 100. 
 
     
     
       4. The high power device according to  claim 1 , wherein:
 the third nitride semiconductor layer is an AlyGal-yN layer (1≥y>0). 
 
     
     
       5. The high power device according to  claim 1 , further comprising a substrate and a buffer layer provided on the substrate;
 wherein the first nitride semiconductor layer is formed on the buffer layer, and 
 wherein the buffer layer is an InaAlbGa(1-a-b)N layer (1≥a≥0, 1≥b≥0). 
 
     
     
       6. The high power device according to  claim 4 , further comprising a substrate and a buffer layer provided on the substrate;
 wherein the first nitride semiconductor layer is formed on the buffer layer, and 
 wherein the buffer layer is an InaAlbGa(1-a-b)N layer (1≥a≥0, 1≥b≥0). 
 
     
     
       7. The high power device according to  claim 5 , wherein:
 the substrate is any one of Si, SiC, α—Al 2 O 3 , ZnO, GaN, AlN and diamond. 
 
     
     
       8. The high power device according to  claim 6 , wherein:
 the substrate is any one of Si, SiC, α—Al 2 O 3 , ZnO, GaN, AlN and diamond. 
 
     
     
       9. The high power device according to  claim 1 , wherein:
 a film thickness of the InN layer is 0.26 nm, and 
 a film thickness of the GaN layer is not more than 20 nm.